Conventionally, printers such as inkjet printers have performed printing using transparent ink (clear ink), for example, as a special recording agent in addition to the color inks cyan, magenta, yellow and black (CMYK) inks. In this case, an effect is typically obtained by application to the entire printable area of the recording medium, although a certain effect can also be obtained by applying the transparent ink to only the image data.
Technology has been disclosed in which an area for using transparent ink is determined based on print data, and transparent ink is applied only to the image. According to this technology, print data for printing generated by an application is read, and an analysis processing unit of a printer driver analyzes the types of data included in the print data for printing. The result of this analysis is digitized as attribute data. Attribute data includes information indicating where image data is located in the printing area. Further, transparent ink is applied to areas with respect to which transparent ink coating “ON” is set in a binarization unit.
Generally, with printing of image data such photographic images that include white portions, gloss unevenness can occur, since portions where ink has been emitted are mixed with other portions of the paper. However, with such print material, transparent ink can be applied to the entire area of the photograph, enabling image quality to be improved (e.g., see Japanese Patent Laid-Open No. 2005-119279).
Meanwhile, there are image forming apparatuses that register form data transmitted from an information processing apparatus in an image forming apparatus as image data onto which transparent toner is to be transferred, and combine registered form data with content data. Here, additional information whose color is transparent is transmitted to the image forming apparatus as form data, together with a command indicating that this form data is additional information whose color is transparent (e.g., see Japanese Patent Laid-Open No. 2009-188816).
Data for printing generated by an application is delivered to a printer driver via an operating system (OS). However, depending on the type of OS or application, a function for correctly delivering data serving as objects may not necessarily be provided. In the case where data is delivered as an erroneous photographic area, such as an area outside the photograph being larger than it should be, for example, transparent ink is applied expansively to portions other than the photograph, with this becoming a new cause for image failure.
Meanwhile, in the world of commercial printing, including offset printing and electro-photographic on-demand printing, the trend is increasingly towards decorating print material using transparent ink and the like. However, such technology requires the provision of sufficient resources on the printer side and the intervention of a skilled operator since complex operations are required, and was conventionally only realized with an expensive, large-scale printer system. Also, the running costs are extremely high.
However, there are strong calls in the marketplace to easily obtain an image with a high level of design sense using transparent ink, even with inexpensive consumer systems such as inkjet printers.